Placer-mining machine



Nov. 6, 1923. 1,473,039 I T. F. HARKINS PLACER MINING MACHINE Filed July29 1922 Patented Nov. 6, 1923.

UNITED STATES PATENT orrica.

THOMAS F, HARKINS, 0F DENVER, COLORADO, ASSIGNOR, BY MESNE ASSIGNMENTS,TO THE LITTLE GIANT MACHINE COMPANY, OF DENVER, COLORADO, A CORPORA-TION OF COLORADO.

rLAcnn-mnme MACHINE.

Application filed July 29, 1922.

To all whom it may concern:

Be it known that I, THOMAS F. Hnnnrns, a

citizen of the United States, residing at the city and county of Denverand State of U010- rado, have invented certain new and usefulImprovements in Placer-Mining Machines; and I do declare the followingto be a full, clear, and exact description of the invention, such aswill enable others skilled in the art to which it appertains to make anduse the same, reference being had to the accompanying drawings, and tothe characters of reference marked thereon, which form a part of thisspecification.

This invention relates to placer mining machines of the type employedfor recover ing fine gold from sand.

In many parts-of our country gold occurs in considerable quantitiesmixed with sand or gravel. The gold has been reduced to very smallparticles by the action of the rocks and sand as they in turn have beenagitated by the streams of water which have flowed over and through themin ages past. Many efforts have been made to recover gold of the kindreferred to above, which is usually referred to as flour gold andmachines of various kinds have been devised for this purpose, some ofwhich have been operated more or less successfully. Most of the placermining machines have been built and operated in such a manner that alarge amount of water has been necessary for their success. Flour goldis found in many places where water is scarce and for this reason manyrich placer mines have never been worked.

It is the object of this invention to produce a machine that shall beadapted to separate from the sands and gravel gold which occurs thereinin the form known as flour gold and'to accomplish the separation by theuse of the leastpossible amount of water. In order to more fully andclearly describe my invention I shall have reference to the accompanyingdrawings in which v I Fig. 1 is a perspective view of my ma chine, v

Fig. 2 is a section taken on line 2-2 Fig. 1, Fig. 3 is a section takenon line 3 3 Fig. 1, Fig. 4 i'sa section taken on line H Fig. 1 and Fig.5 is a section taken on line 5-5 Fig. 4:. The same reference characterswill be Serial No. 578,440.

used to designate the same parts throughout the several views.

My machine is supported on a framework comprising a pair of parallelbase members 1 near the end of which I provide four vertical supportingmembers 2. An inclined timber 3 extends on each side from the rear ofone of the vertical members 2 to the end of members 1, as clearly shownin Fig. 1. Short spacing members 4 extend between the timbers 1 and 3 tomake the latter rigid. The framework is mounted on cross ties 5 whichmay be sunk into the ground when the machine is installed for operation.A framework 6 is supported from the members 3 by means of links 7 whichare rotata bly mounted in the bearings 8 and are similarly connected attheir upper ends of boxes A cross piece 10 joins the parallel mem bersof the frame 6 and a number of springs 11 join the cross piece 10 withthe vertical framework formed by the members 2 (Fig. 2). Springs 11 areunder tension and tend to hold the framework 6 in its uppermostposition. A buffer 12 extends transversely of the frameworkand serves asa stop for limiting the upward movement of the frame 6. Secured to theframe 6 and cooperating with the buffer 12 are a pair of members 13which are firmly secured to the sides 6 by means of bolts 14. The upperend of the members 13 are provided with resilient cushions 1 5 forengaging the buffer 12 and are connected near their ends by a transversemember 16. A shaft 17 is rotatably mounted in bearings 18 and carriescams 19 which cooperate with the rollers :20 which are connected to themembers 13. Asthe cams are rotated in the direction of the arrow (Fig.2) they engagethe rollers and moves them towards the right. thustensioning the springs 11. As the rollers pass over the tips of the camsthe springs become free to operate and as they contract the frame 6 ispulled upwardly with'a quick motion and the ends of the cushions 15strike the buffers 12 when the movement suddenly stops the quick upwardmovement and the sudden stop performs an important function in theoperation of the machine and will be re ferred to hereafter. Secured, bysuitable means, to the upper end of frame 6 is a rifiie table which Ishall designate as a whole by numeral 21. This table consists of twospaced side members 22 each of which is made up of two cooperatingmembers 22 and 22*, the lower one (22) of which is cut in the form of astair member. The upper portion of each step is notched as indicated ynumeral 23.

The upper member is made to cooperate with the lower one so as to clampbetween them a piece of sheet metal 24 which is bent so as to conform tothe contour of the co operating edges of the two pieces 22 and 22. Itwill be seen from an inspection of Fig. 2 that the sheet metal. bottom24: forms a structuresimilar to a stair. The portions of the stair thatbends downwardly so as to conform to the portion 23 forms a transversetrough or rifile 25 into which the gold and heavier minerals willgravitate when the machine is in operation. In each trough 25 I place astirring member which is preferably formed from a pipe and has threerows of screws 27 that project towards the walls of the trough 25 in themanner shown in Figs. 2 and 4. The pipes 26 are rotatably mounted ateach end between the ends of the springs 28 and has an arm 29non-.rotatably secured thereto at a point about equidistant from theends. A rod 30 joins all of the arms 29 in the manner shown n Fig. l andhas its upper end connected to a stationary part of the framework. It isevident that as the table reciprocates the pipes 26 will be oscillatedby the action of rod 30 and arms 29 and that the screws 27 will keep thesediment agitated within the troughs '25 so as to prevent the same fromcaking. The auriferous sands that are to be treated are shoveled into acontainer or box 31 whichhas an adjustable opening 32 in the bt tomthereof. The opening may be varied in size by means of plates 33. Anauger like member 34 cooperates with the container 31 and serves todistribute the material to several machines where the capacity is to beaugmented. Each machine is provided with a water tank35 which has one ormore openings in its bottom: these openings may be partly or entirelyclosed by a needle valve 37 Water is conducted to the tanks 35 through apipe 38.. Beneath the container 31 and the tank 35 I provide a chute 39hav ng a corrug t d et l om 40 wh h projec ve h uppe en of. e le nddirects the mixture of sand and water onto t e me The machi s v n hro gha belt. 41 app d o he wheel 42. A sp ck t %3 extends. fr ma pro et he ln the axle o the Wh e 42 to a si ar whe l an. the an hat: 17- A fla e i4i l t d benea h he le elf'end of th table 21 and er es. to arry away te. material as it leaves t chine The table 21 is made up a a n mb r secion so hat it c n. be new easily hand ed when t e clean p is madelendeto hold th var ou secti ns 1 ,rrsneo of the table firmly on the frame 6I provide a plurality of ears 45 which have their lower ends secured tothe frame 6 and their upper ends provided with openings for thereception of rods 46. In order to prevent the metal bottom plate 2%fronrwearing out, I provide the same with an extra plate 47 which I calla half sole; this plate protects the lower plate and can be quicklyrenewed and replaced when it is worn out.

The operation of my machine is as follows: The machine is driven by agasoline engine or an electric motor to which the belt 41 is directlyconnected and as the wheel 42 is rotated the screw 34 turns and movesthe material along the container, some of the material drops through theopening 32 and into the chute where it mixes with'tho water from tank35. The wet material then passes from the chute onto the rifile ta le21, which is constantly reciproeated through the action of the cams 19and the springs 11. As the material flows over the table the troughs 25are filled with the Same and the gold and heavier particles or mineralswill gravitate to the bottom. The slow downward movement of the tableand the quick upward movement thereof serves to move the materialdownwardly as the inertia of the material will cause it to remainstationary as the table is quickly moved upwardly by the springs 11. Thegreater part of the gold will be separated out in the troughs near thetop, but anything that escapes the first troughs will be ca turedfurther down as a considerable num er of troughs are provided.

From the above it will appear that I have devised a machine of simpleand substantial construction that can be cheaply constructed and easilyassembled, which is adapted to be transported to distant places by meansof trucks of moderate capacity. My machine is so designed that anynumber of them can be arranged side by side so as to provide capacityfor any amount of material. The construction is such that the gold canbe readily removed so as to reduce to as small a period practicable thetime the machine needs to be kept idle for cleaning.

I h v s provided means whi h continu:

a ly keeps the mat ial ti red up n the collec ing pocke s where y he samis prevented from caking.

Having now described my invention, what I claim as newis:

1. In a placer mining machine n can bin ion a upp r ng'fmme or an clinedriflie table having parallel sides mp,

ported on said framework: and adap fldf oscillate with respect, thereto,transverse p cke s in. s id table, a. stirring elemen pivotallyconnected to said sides to; 60: Qper ing with said pockets. can; me ns fr moving said table in the rlewmmd dir tion, spring means for movingsaid table in the upward direction with a quick motion, stops adapted tobe engaged by the table in its uppermost position and means for feedinga mixture of sand and water to the upper end of said table.

2.In a placer mining machine, in combination a supporting framework; aninclined riifie-table having transverse pockets a-ndsubstantiallyparallel sides supported on said table and adapted to oscillate withrespect thereto, said table being formed in separable sections; arotatable stirrer in each pocket, said stirrer being pivotally andremovably mounted between the sides of the table; an upward projectingcrank-arm se cured to. each stirrer; and a bar connecting said lever toa stationary part of the frame, whereby when the table reciprocates thestirrer will be oscillated about its pivots.

3. A riifie-table for placer mining machines comprising twosubstantially parallel sides, each of which is made of two parts havingcooperating edges adapted to fit the edges of a metal rifile bottom,said bottom being provided with transverse pockets, the portions of saidbottom between said pockets being protected against wear by a removablepiece of metal.

In testimony whereof I afiix my signature.

THOMAS F. HARKINS.

